METHOD OF THERMAL TREATMENT OF CUTTING TOOLS MADE OF HIGH-SPEED STEEL Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: novel method included two steps of thermal treatment. First, tools were many times heated to temperature of 610 C A₁ and oil cooled, repeatedly heated and cooled within temperature range from melting point and temperature at which martensite transformations began. Tools were then finally hardened from temperature of last heating in thermal treatment and annealing. At the second stage of thermal treatment, tools were isothermally processed in chloride melt in which carbonate and carbide were additionally introduced. Barium or potassium carbonate was employed as above mentioned carbonate and silicon or potassium carbide was used as above carbide. Using disclosed method of thermal treatment gave rise to reduction of structural components, great structural homogeneity, and high degree of alloying of solid solution by chemical elements. EFFECT: substantially higher durability of wood-cutting tools. 2 cl, 2 tbl